3 ms·

Now, rendering at 60 fps you've got to render in 16ms. This actually turns out to not be much time in a networked environment. Not true. Human reaction times a

Now, rendering at 60 fps you've got to render in 16ms. This actually turns out to not be much time in a networked environment. Not true. Human reaction times are 180 to 200 milliseconds for visual stimuli. That's the limit on your pipeline. You still need to render once every 16 ms, but it can take longer for each frame to get there than that.

reitzensteinm 18y ago
Reaction times might be 180-200 milliseconds, but a delay in rendering (as in a pipeline delay, so 60fps rendering but 180ms delay) will add to the reaction time latency, it won't be masked by it. If you delay rendering by 180ms, then the screen will change 180ms after you hit a key, and you'll only notice the result after your reaction time for a total of 360ms. I'd bet even 50ms will feel a bit sluggish subconsciously (people won't like your controls but they won't know why), but delaying by 180-200ms will make your character noticably lag input. I could easily whip something up to simulate it if you'd like.
- DaniFong 18y ago
  That's true, but my main point was you don't really have time to react to something being 'out of sync'. It might feel a little sluggish, but only just. (I suspect)
  - reitzensteinm 18y ago
    Hmm, I think you're probably underestimating the impact. I've made a little test program that you can play with yourself - if you've got a Windows machine around at all: http://www.rocksolidgames.com/latencytest.exe http://www.rocksolidgames.com/latencytest.exe Source is at: http://www.rocksolidgames.com/latencytest.bmx http://www.rocksolidgames.com/latencytest.bmx (written in BlitzMax) I can't notice 1 frame of latency (16ms per frame), but 2 doesn't feel quite right, and by 4 frames (~64ms), the controls clearly feel lagged to me. Of course, considering my day job I play a lot of games and troubleshoot problems like this, so I'm probably more sensitive than average to something like this. My gut feeling is that anything over 40-50ms is unacceptable. So you could have a render pipeline three stages deep at 60fps, but there's no way I'd go deeper than that. Also, if you've got any external latency in a game (i.e. multiplayer net play), the budget is already blown and any kind of latency at all is unacceptable.
    - DaniFong 18y ago
      Wow, thanks for this demonstration. There are still a lot of surprises in sensation, it seems.
      - reitzensteinm 18y ago
        You're welcome! It was educational for me too, I had never tested render latency in isolation.

reitzensteinm 18y ago

Reaction times might be 180-200 milliseconds, but a delay in rendering (as in a pipeline delay, so 60fps rendering but 180ms delay) will add to the reaction time latency, it won't be masked by it. If you delay rendering by 180ms, then the screen will change 180ms after you hit a key, and you'll only notice the result after your reaction time for a total of 360ms. I'd bet even 50ms will feel a bit sluggish subconsciously (people won't like your controls but they won't know why), but delaying by 180-200ms will make your character noticably lag input. I could easily whip something up to simulate it if you'd like.

DaniFong 18y ago
That's true, but my main point was you don't really have time to react to something being 'out of sync'. It might feel a little sluggish, but only just. (I suspect)
- reitzensteinm 18y ago
  Hmm, I think you're probably underestimating the impact. I've made a little test program that you can play with yourself - if you've got a Windows machine around at all: http://www.rocksolidgames.com/latencytest.exe http://www.rocksolidgames.com/latencytest.exe Source is at: http://www.rocksolidgames.com/latencytest.bmx http://www.rocksolidgames.com/latencytest.bmx (written in BlitzMax) I can't notice 1 frame of latency (16ms per frame), but 2 doesn't feel quite right, and by 4 frames (~64ms), the controls clearly feel lagged to me. Of course, considering my day job I play a lot of games and troubleshoot problems like this, so I'm probably more sensitive than average to something like this. My gut feeling is that anything over 40-50ms is unacceptable. So you could have a render pipeline three stages deep at 60fps, but there's no way I'd go deeper than that. Also, if you've got any external latency in a game (i.e. multiplayer net play), the budget is already blown and any kind of latency at all is unacceptable.
  - DaniFong 18y ago
    Wow, thanks for this demonstration. There are still a lot of surprises in sensation, it seems.
    - reitzensteinm 18y ago
      You're welcome! It was educational for me too, I had never tested render latency in isolation.